The present invention relates to an apparatus for sealing packaging containers formed at least partially of a bondable material, the sealing being effected under the action of pressure and heat. The present invention relates, more particularly, to such an apparatus having a first bonding unit and a second bonding unit.
Many spoilable foodstuffs are nowadays packed in containers which are made at least partially of a bondable plastic material and which are sealed by means of a bonded seam. As the reliability of the sealed tightness of the closing seam is considerably increased if it were finished with a double bond, it is the current practice to provide a first bonded seam with a first bonding tool and, after the first seam has hardened, to apply a second bonding seam with a second bonding tool to effect closure of the container. The two bonded seams may cover each other, may partially cover each other or they may be disposed parallel to each other with a slight distance or no distance therebetweeen. The two bonded seams may be of identical width or may be selected such that the first bonded seam is wider than the second bonded seam.